diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 4b6920de2541..af62c75b17c4 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1305,6 +1305,11 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 	iov[1].iov_base = unc_path;
 	iov[1].iov_len = unc_path_len;
 
+	/* 3.11 tcon req must be signed if not encrypted. See MS-SMB2 3.2.4.1.1 */
+	if ((ses->server->dialect == SMB311_PROT_ID) &&
+	    !encryption_required(tcon))
+		req->sync_hdr.Flags |= SMB2_FLAGS_SIGNED;
+
 	rc = smb2_send_recv(xid, ses, iov, 2, &resp_buftype, flags, &rsp_iov);
 	cifs_small_buf_release(req);
 	rsp = (struct smb2_tree_connect_rsp *)rsp_iov.iov_base;